Counterbalancing apparatus



sept' 23, 1.941- R. w. BIER 2,256,605

COUNTERBALANCING APPARATUS Filed June 3, 1959 3 Sheets-Sheet l Sept. 23, 1941 R, W B|ER 2,256,605

COUNTERBALANCING' APPARATUS Filed June 3, 1939 s sheets-sheet 2 Sept. 23, 1941.

COUNTERBALANCING Filed June 3,

R. W. BIE R APPARATUS I5 Sheets-Sheet 3 Patented Sept. 23, 1941 UNITED STATES PATENT OFFICE` COUNTERBALANCING APPARATUS Robert W. Bier, Houston, Tex.

Application June 3, 1939, Serial No. 277,184

Claims.

This invention relates to new and useful improvements in counterbalancing apparatus.

One object of the invention is to provide an improved counterbalancing apparatus which is particularly adapted for use on well pumping units and which is arranged so that it will eiliciently counterbalance the load during a pumping, hoisting, or other operation.

An important object of the invention is to provide an improved counterbalancing apparatus wherein the counterweight may be adjustably locked in any position around the crank arm, whereby an infinite counterbalancing effect from minimum to maximum may be obtained.

vA particular object of the invention is to provide an improved apparatus, of the character described, including a crank arm which is readily adjustable to any desired length between minimum and maximum, whereby an innite stroke adjustment from minimum to maximum may be obtained and also whereby excessive wear on the gearing is obviated, which increases the life of the apparatus; the infinite stroke adjustment also making possible the use of a single wrist pin of suicient size to prevent breakage of said pin, whereby more eiilcient operation is had.

Another object of the invention is to provide an improved counterbalancing apparatus including an adjustable crank arm having its counterweight arranged to be adjusted therearound, whereby-the counterweight may be adjusted so that either proper counterbalancingA for normal operation or any desired counterbalancing effect for back cranking may be readily secured, which makes the apparatus particularly advantageous and most practical in actual use.

Still another object of the invention is to providean improved apparatus, of the character described, having a circular supporting member eccentrically mounted on the power or drive shaft so as to be rotatable therewith, with a ring surrounding the member and rotatably adjustable with relation thereto, said ring being adapted to be connected to the operating pitman, whereby the distance between the power shaft and the point of connection of the pitman to the ring determines the length of the crank arm; the mounting of the ring on the supporting member making it possible to quickly and easily move the ring to various adjusted positions to vary the length of the crank arm and thereby change the length of the pitman stroke. Y

A further object of the invention is to provide an eccentrically mounted supporting member which is constructed so as to be properly balanced and having a ring adjustably mounted thereon, which ring permits variation in the length of the crank arm, together with a counterweight adjustably mounted on the ring, whereby the proper stroke length and proper counterbalancing effect may be readily obtained; the crank arm being variable separately of the adjustment of the counterweight, whereby each may be individually adjusted without effecting the other. Y i' A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specication and by reference to the accompanying drawings, in which an example of the invention is shown, and

wherein:

Figure 1 is a side elevation of a Well pumping rig, showing an improved counterbalancing apparatus associated therewith,

Figure 2 is a side elevation of an apparatus constructed in accordance with the invention,

Figure 3 is a view similar to Figure 2 and showing thecounterweight moved to another position,

Figure 4.- is a horizontal, cross-sectional View, taken on the line 4 4 of Figure2,

Figure 5 is a side elevation of the inner circular supporting member, Y

Figure 6 is a side elevation of the ring on which the counterweight is mounted,

Figure 7 is an enlarged, transverse, sectional View taken on the line 1-1 of Figure 6,

Figure 8 is a side elevation of the counterweight, Y

Figure 9 is a view similar to Figure 2 and illustrating a slightly modified form of the invention wherein two counterweights are employed.

Figure 10 is a horizontal, cross-sectional View, taken on the line lll-l0 of Figure 9,

Figure 11 is a side elevation of a modied form of the apparatus,

Figure 12 is a view similar to Figure 11 and showing the counterweight, as Well as the ring, moved to another adjusted position,

Figure 13 is a side elevation of the supporting member in this form of the invention, l

Figure 14 is a side elevation of the weight supporting ring, and

Figure 15 is an enlarged horizontal, cross-sectional view taken on the line |5--I5 of Figure 11.

In the drawings, the numeral l0 designates a walking beam which is pivotally mounted on the upper end of a suitable post I l in the usual manner. One end of the walking beam is provided with the usual arcuate head I2 which has conadapted toY be reciprocated by means of a pitman |6 which has its upper end pivoted to the end of said beam. The lower end of the'pitman is connected, through a wrist pin |1 and through the improved crank arm and counterbalance apparatus A, which forms the present invention, to a" crank shaft |8. The crank shaft I8 may be driven by any suitable motor, lor other drive l5 mechanism. Manifestly, when the Vcrank shaftl l |-8 is rotated, the pitman is reciprocated to swing the walking beam IIJ, wherebythe pump rods I4 are reciprocated and the pumping operationperf-= formed.

VThe counterba-lancing apparatus includes a cicularf'dislc or' supporting member I9 which is provided with an. offset hub 20. The hub is lolocked in various adjusted positions around the disk. Y

The transverse width of the ring is less than the transverse width of the rim 24 of the disk (Figure 4) and an outwardly directed annular ilange 36 is provided on the outer edge portion of said ring. After the ring has been placed on the disk or :supporting member, a weight member 31 is arranged to be mounted on the ring. As is clearly shown in Figure 8, therweight member includes a split ring portion 38 which has an arcuate or segmental weight 39 preferably made integral therewith. An annular rib 40 is formed on the inner surface of thering portion 38 a-nd this rib is adapted to engage the periphery of the ring 3|, as is clearly shown in Figure 4. V.One side of the rib 46 engages the annular flange 36 on the ring 3|, while the other side of the rib 40 is engaged by a retaining element or ring 4I, which element surrounds the disk I9 and is secured by bolts 42 to the ring 3|.: The provision of the retaining element 4| forms an annular groove Vbetween said element and the cated-'nn-center'or eccentricauyof the disk 'and issplit at 2|',wher'eby thecrank shaft I8 may befinsert'edtherein. YSuitable bolts `22 are pro- 3 Vvided tojlti'g'hten' the hub around the shaft and, g in."'a'dditior'L' a keyway'23 is provided, whereby said hubrmayA be'V keyed tothecrank shaft..- In

this manner, the 'circular `disk or supporting memher'lSsv/mounted'on the :crank shaft so as to be rotatable therewith. The diskV is formed v .with a fiati-im 24 which' is connected tothe hub by' a web' 25,'said' web being reinforced by suitablev ribs'f2l6 which Yextend. radially from the hub.

25 is providedA with an elongate slot 2l, which Slot formsa continuation of the split portion 2|,

whereby'tightening of the hubaround the shaft may be accomplished. Adjacent the hub 28 ofv 1 the disk is anenlarged boss or solid portion 28 i which is constructed of a solid metal. The weightof this bossrserves to counterbalancejv the remfainder'pf the disk, whereby said disk, al-

A ring`3| surrounds the disk orxsupporting member 9'v and has an inner` diameter substantially 'equal tothe outer diameter of said disk,- j whereby said ring may be rotatably mounted on i said disk. The ring isV preferably split and is l formed with-a'vplurality of inwardly directed ears 3.2,nfeach of whichv is provided with an opening flange 24a provided on the` rim 24, while the ears 32 on said ring abut one side of the rim 24, as is clearly shown in Figure 4. The openings 33 in the ears V32are1adapted `tobe alinedwith certain ofthe-'openings 3D intheV disk, whereby bolts 1 34rmay berpassed through these registering openings.; The ,bol-ts 34 receive nuts 35, whereby the 1 vringisimountedin a xed .position on the disk. Manifest-ly;` the provision of 'the plurality of openings 'in 4the disk permits the ring to be 75 Adjacent the split portion- 2| ofthe hub, the web 33.Y When the ring is' in position on theY disk, i one sideof the ringabuts an annular peripheral an'ge 36 and the rib 40 of the weight member.` Y

31 'is confined within said groove, whereby the member 31 is rotatably mounted on the ring 3|. Obviously, since theY retaining element 4I is removable, the mounting and removal of the -weight member 31 sfacilitat'ed.

For' fastening the weight member 31 in' its various adjusted positions on the ring 3 I the splitr vportion of 'the weight member is formedV with lugs 43 through which atightening bolt44 ex`` tends. Afterv the weight, is ,moved to its 'proper position relative to the ring 3|, the vbolt 44 is tightenedY to hold the same'in such position? To further aid in holding the weightlme'mber 31 in its adjusted position on the ring, theperipheral portion of said ring may b'e formed with a plurality of lnotches 45. These notches are spaced around the ring, as is clearly shown in Figures V3 and 6, and are adapted to registerwith to anyr peripheral position relative to the ring Y 3|. The notches 45 and 46, as well as the key or keys 41, are not essential and may be omitted,

in which event the clamping of the ring portion 38 around the ring 3| is depended upon to hold Y the weight member in its adjusted position; or,

if desired, other means of maintainingv theY weight in its various adjusted positions may be provided.

The ring 3| Yis providedy with an opening 48V which extends entirely therethrough (Figure '4), The retaining ring or elemenit4| is formed with an opening 49 which-is adapted to register with',V

tatable therewith. The ring 3| is then-mounted on the periphery of the disk I9 and is secured in its proper position thereon by the bolts 34 and .nuts 35. Since the wrist pin I1 is secured to the ring 3|, it will be manifest that the distance between the crank shaft I8 and the wrist pin I1 controls the length of the crank arm, which arm is formed between these two points. Since the disk is eccentrically mounted on the crank shaft and also since the ring is movable around the periphery of said disk, it will be obvious that the opening 48 may be moved relative to the crank shaft I8. Such movement of the opening 48 is accomplished by rotating the ring 3| on the disk and, as said opening is moved, the crank arm is reduced or lengthened according to such movement. Thus, the length of the crank arm is capable of infinite adjustment between minimum and maximum. It is Wellknown that the length of the crank arm will change the stroke of :the pitman, thereby changing the pumping stroke.

The weight member 31 is rotatably mounted on the ring 3| and may be adjusted t0 any position thereon. This makes it possible to adjust the counterweight 39 with reference to the crank arm `so as to provide for either lag or lead. Thus, the arrangement permits any counterbalancing eiect to be obtained. The weight may be adjusted for proper counterbalancing during normal operating or to obtain any counterbalancing effect necessary for back cranking. The adjustments are accomplished readily and with minimum effort and the parts are positively locked in their adjusted positions to prevent accidental displacement. Manifestly, the crank arm may be varied in length either individually and separately of the adjustment of the weight member or simultaneously therewith.

In Figures 9 and 10, a slightly modified form of construction is shown. In this form, the weight member 31 is omitted and a pair of weight members 31 are substituted therefor. These members are constructed substantially the same as the member 31 except that the weight portion 39 of each is less than the Weight portion 39 of the rst mentioned weight 31. Also, the tranverse Width of the Weight members 31 is only half that of the weight member 31, with the result that both members 31 may be mounted on the periphery of the ring 3|. By using two weights instead of one, it is possible to obtain a Wider adjustment ordistribution of the weight. The operation of this form is substantially the same as that hereinbefore described.

In Figures 11 to I5, still another form of the invention is shown. In this form, a split hub 53 is adapted to be secured to the crank shaft I8. A circular disk or supporting member is preferably made integral with a supporting arm 52, which arm is, in turn, integral with the hub 50. In this manner, the supporting disk 5I is located or disposed at one side of the hub, whereby said disk is offset from the crank shaft I8. A ring 53 surrounds the supporting disk 5I and is provided with inwardly directed ears 54 having openings 55 therein. The openings 55 are adapted to register with a plurality of openings 56 which are spaced around the rim 5I' of the disk. The provision of the openings 55 and 56 permits the ring to be moved to various positions around the disk and to be fastened in such adjusted positions by bolts 51 which extend through the registering openings. For counterbalancing the weight of the disk 5I Which is offset from the crank shaft, a counterweight 5Ia, which is preferably integral with the hub, is disposed diametricallyopposite the disk and this weight serves the same purpose as the weighted boss 28 in the other forms to balance the disk.

As is clearly shown in Figure 14, the inner periphery or surface of the ring 53 is offset or eccentric with relation to the outer periphery of said ring. An opening 58 is provided in the wide portion of the ring 53 and this opening is adapted to receive the wrist pin I1. Obviously, when the Wrist pin is connected inthe opening 58, the distance between said opening and the crank shaft I8 controls the length of the crank arm formed therebetween. f By rotating the ring 53 to various adjusted positions on the supporting disk 5|, the distance between these points may be varied, with the result that the length of the crank arm is also varied. Iminite adjustment between minimum and maximum may be thereby obtained.

A pair of weight members 31a, which are similar .in construction to the weights 31', are mounted on the outer periphery of the ring 53. These weights are mounted in the same manner as are theweights 31 and 31 in other forms hereinbefore described. The mounting of the weights 31a, being the same as the mounting of the weights 31 and 31', said weights '31a may be moved to any desired adjusted position on the ring 53, whereby any desired counterbalancing effect may be produced. It is pointed out that itvmay be desirable to add additional weights to the weight members 31a. For this purpose, a plurality of openings 59 are formed in the Weight members 31a, whereby additional weights 6U, shown in dotted lines in Figure 15, may be added to the members 31a, being secured thereto by suitable bolts. In this form, the same innite stroke adjustment as well as innite counterbalancing eifect may be obtained. It is noted that, if desired, additional Weights may be added to the weights 39 and 39' of the other forms, in this same manner. Also, the eccentric ring 53 may be substituted for the ring 3| in said other forms.

- In all instances, infinite stroke adjustment and infinite counterbalancing effect between minimum and maximum vmay be had.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, Within the scope of the appended claims, Without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. A counterbalance including, 'a circular support adapted to be eccentrically mounted on a crank shaft, a ring adjustably mounted on the support and adapted to receive a wrist pin, and a weight mounted on the ring and capable of adi justment therearound.

' 2. A counterbalance for crank shafts including, a circular support mounted eccentrically on and rotatable with ,a4 crank shaft, means adjustable around the support and having provision for mounting a wrist pin thereon whereby said pin l is movable toward and away from the crank chaft movable towardand away from the crank shaft to varythe distance therebetween and thereby vary the effective crank length, and a weight adjustably mounted on said means and capable of movement therearound, whereby said weight may be positioned:circumferentially to obtain the desired balance. A l Y f 4. A counterbalance for crank shafts including, a circular support mounted eccentrically on and rotatable with a crankshaft, means adjustable around the support and having provision for mounting a wrist pin thereon whereby said pin c therebetween, means for locking saidV means in adjusted positions on the support, a weight mounted on saidadjustable means and capablev of movement therearound, whereby Vthe weight may be .positioned circumferentially `to obtainv thel desired balance, and means for locking the weiglfitA in its various adjusted positions.

V6. A counterbalance for crank shafts including,`

a'crank arm adapted to be secured to the crank `shaft and rotatable therewith, said arm including two elements which'are movable'relative to each other for varying the effective length of the crank Vfrom minimum to maximum, a weight mounted Aon said arm, and means for positioning the weight at various radial positions relative to the shaft to obtain the desired balance.

' '7. A counterbalance for crank shafts including,

a crank armadapted to be secured to the crank shaft and rotatable therewith, said arm includingv two elements vwhich are movable relative to each other, for varying the effective length of the Y crank from 'minimum vto maximum, a weight mounted on said armmeans for positioning the weight at various radial positions relative to thev shaft to obtain the desired balance, and means for lockingV the weight in its various adjusted positions. 'i

` 8. VA adapted tobe mounted lon a crank shaft which is offset with vrelation thereto, a ring adjustably mounted Yon the support and movable around the crank shaft, a wristl pin mounted on the ring,

` anda counterweight adjustably mounted lon said:

ring.

9. A counterbalance for ing, a support eccentrically mounted on the crank shaft and having an annular rim, a ring rotatably mounted on the yrim and movable therearound, a wrist pin carried by the ring, means for clamping the ring in various adjusted positions on-the rim to hold the pin in xed positions relative to the crank shaft, and a counterweight Vcour'iterbalance including, a support adjustably and rotatably mounted on Ythe -rng and movable to various positions around the same.`

10. A counterbalance for a crank shaft including, a support eccentrically mounted on the crank shaft and having an annular rim, aring rotatably mounted on the rim and movable therearound, awrist pin carried by the ring, means for clamping the ring in various adjusted positions on the rim to hold the pinin fixed'positions relative to the crank shaft, a counterweight adjustably and. rotatably mounted on the ring and movable to various positions'around vtheA same, and means for locking said lweight in its` various adjusted positions. 'Y i 11. A counterbalanceincluding, a circular support, a hub secured to the support and disposed radially thereof, said hub being adapted toV be mounted on a crank shaft, an eccentric ring rotatably mounted on the support, a wrist pin carried by the ring; means for fastening the .ring in various adjusted positions'on the support, and

' a counterweight adjustably mounted on the ring.

a .crank shaft includ- 12. A counterbalance for crank shafts including, a crank arm adapted to be secured to the crank shaft and rotatable therewith, said arm including two elements which are movable relative to each other for varying the effective length of the crank from minimum to maximum, weights mounted on said arm, and means for Vpositioning the weights at various radial positions relative to the shaft and to each rother to obtain-the desired balancing effect.

. 13. A counterbalance for orankshafts including, a crank arm adapted to be secured to the crank shaft and rotatable therewith, said arm including two elements which are movable relative to earch other for varying the effective length of the crankV from minimum to maximum, wei-ghts mounted on said arm, means for positioning the weights at various radial positions relative to theV shaft and'to each other to obtain the desired balancing effect, and means for holdingtheweights in theirv various adjusted positions. Y

14. A counterbalance including, a support adapted to be mounted on Ya crank shaft which is offset with relation thereto, means for balancing the support, aA ring adjustably mounted on the support and movable around the crank shaft, a wrist Apin mounted on the ring, and a counterweight adjustably mounted on said ring.

15. A counterbalance for a crank shaft including, a support eccentrically mounted on the crank shaft and having an annular rim, means asso- -ciated with said support for balancing the support on the shaft, a ring rotatably mounted on the rim and movable therearound, a wrist pin carried by the ring, means for clamping the ring in various adjustedV positions on the rim to hold the pin inY fixed positions relative to the crank shaft, and a counterweight adjustably and rotatably mounted on the ring and movable to various positions around the same.

ROBERT W. BIER. 

